Moreover the propensity for algal flagella to be deformable by hydrodynamic loading [1]} – e.g. flows generated by nearby flagella, suggests an internal coupling must be present to compensate in such cases where fluid interactions are contrary to the desired mode of propulsion by flagella in the organism.
Given this delicate interplay, will a dramatic perturbation to the state of hydrodynamic interactions between flagella affect their native mode of coordination?
For this we require an organism with more than two flagella.
Tetraselmis is a thecate quadriflagellate, and amenable to micromanipulation.
Fig. REF A depicts a pipette-immobilized Tetraselmis cell with flagella free to beat in a pattern
qualitatively similar to free-swimming cells observed under identical conditions (see SI Video 4),
in which flagella maintain a transverse gallop (next section, and Fig. REF D).
One flagellum was then trapped inside a second pipette with suction so as to completely stall its beating, with minimal disruption to the cell.
Flagellar dynamics were monitored and interflagellar correlation functions computed (Fig. REF B),
showing that the prior beat patterns continue (Fig. REF C).
The small increase in beat frequency in the remaining flagella (\(\sim 5\%\) ) is consistent with calcium-induced frequency elevation by mechanosensation.
This remarkable ability for the cell to sustain its coordination pattern strongly implicates internal beat modulation.
